This is my first attempt at writing a science fiction short story.

Nine thousand Old-Earth years after the invention of Faster than Light travel, the physicist Marcus Dios imagined what would eventually become known as humanity’s greatest science experiment. The Prometheus Simulation began as a seed in Dios’s mind. It soon became a plan, then a project proposal, and finally a full project adopted by the Interplanetary Institute of Science. Humanity had various goals for the Simulation. The astrobiologists wanted to know what forms of life would develop in a simulated universe. The theoretical physicists wanted to study how different physical laws would behave. The philosophers wanted to get a better understanding of the nature of consciousness. And the computer scientists just wanted to show it could be done.

Researchers from across the galaxy came together to develop the fundamental physical laws of the Prometheus Simulation. An initial suggestion was to simply recreate the physics of the human universe by writing code to describe the interactions of atoms and molecules, perhaps all the way down to the quantum behavior of quarks. But since Prometheus was the first simulation taking place on such an astronomical scale, the physicists and the computer scientists agreed to create a simplified set of Physical Laws that would be easier to simulate.

It was decided that the entire simulated universe would consist of a three-dimensional binary matrix of length \(2^{50}\) in each direction. Each cell of the matrix would contain a single bit: a \(0\) or a \(1\). After each “tick” of the Simulation, the state of the entire matrix would be recalculated from its previous state; \(0\)s flipping to \(1\)s and vice versa according to the Laws. The Laws were completely deterministic, resembling those of the cellular automaton called The Game of Life (created by a mathematician named Conway from Old Earth). A \(1\) would flip to a \(0\) if it was in the vicinity of a certain pattern of bits. A \(0\) would flip to a \(1\) if it was surrounded by a different pattern of bits. If the researchers had done their calculations right, on a macroscopic scale the Laws would behave similarly to the way gravity, electromagnetic forces, light, and energy operate in the human universe.

The Simulation’s matrix was seeded with an initial configuration of bits that the researchers believed would produce the most interesting behavior. It contained a large sphere of “solid matter” (or rather, configurations of bits that were predicted to behave analogously to solid matter) upon which lakes and oceans of “liquid matter” circulated in an atmosphere of “gas.” The humans hoped that this watery planet of bits, Prom, would produce life just as Old Earth had produced their distant ancestors.

The Simulation was to be run on a supercomputer the size of a planet, powered by a Dyson sphere that captured the majority of the energy output of a medium-sized star. The supercomputer was fast enough to run \(10^{18}\) Simulation ticks (one exatick) per second of real time. Drawing a rough analogy between the scales of physical phenomena in the human universe and the corresponding “physical” phenomena in the Simulation, it was predicted that this was a speed-up of about three orders of magnitude. In other words, the supercomputer could calculate events in the Simulation a thousand times faster than analogous events would have occurred in the human universe. By leveraging certain heuristics, the computer could run through ticks even faster as long as the Simulation did not have too many complex interactions (such as those occurring in the tissues of a living organism). This would allow the scientists to speed through potential eons of Simulation time before life formed. Even so, the project would likely last many human lifespans, so the Prometheus Colony – an entire city of the galaxy’s most brilliant scientists, engineers, and philosophers – was established on the surface of the supercomputer to monitor and study the Simulation’s progress.

After centuries of planning, the Prometheus Simulation was ready. Humanity held its breath as Cynthia Dios – the head engineer and great-great-granddaughter of the original Marcus Dios – flipped on the power switch. Let there be light. The supercomputer let out a low planet-shaking hum as it started its monumental computational task. Everyone watched on their telescreens as the simulated planet of Prom immediately collapsed in on itself, forming the equivalent of a black hole. Back to the drawing board.



Prom 20 was the first run in which the planet remained gravitationally stable. By Prom 57, the researchers had tweaked the initial conditions enough to keep the atmosphere around for a couple of zettaticks. Prom 203 was the first planet that the biologists deemed capable of producing complex life, but nothing ever happened besides the occasional volcanic eruption. The decades went by, and Prom after Prom, the scientists of the Prometheus Colony began to give up hope. The interplanetary government threatened to withdraw funding.

But then they reached Prom 662. It started out like all of the others, but by around exatick \(10^{13}\), the researchers started to observe small, highly-structured clumps of molecules start to form in certain lakes on the planet. The exact mechanisms that were occurring inside these clumps (which the researchers named “promcells”) were hard to understand, but it was determined that the promcells had developed the ability to replicate by passing on copies of certain fibrous substructures. The researchers were excited to discover that these fibrous substructures had the potential to store genetic information, just like DNA. Eventually, promcells began grouping up with other promcells to form larger clusters. These were Prom’s first multicellular organisms.

Life in the Simulation progressed much as life on Old Earth did. As the organisms grew larger and larger, they began to evolve offensive features (sharp teeth and jaws) and defensive features (hard shells and spines). By around exatick \(5 \times 10^{13}\), the oceans of Prom were teeming with creatures of all sizes, from whale-like behemoths to small organisms reminiscent of algae. A thriving ecosystem of simulated life. Soon the surface of the planet was covered in large stationary organisms that the researchers named “promtrees.” Aquatic life forms evolved legs and wings, eventually migrating onto land and into the heights of the promtrees.

Evolution on Prom was helped along by the researchers’ careful oversight. Every time a large shift in the climate or a supervolcano had the potential to become a major extinction event, the researchers would pause the simulation and carefully edit the matrix to remove the threat. But they only had to do this occasionally. For the most part, simulated life would find ways to adapt and overcome any environmental obstacle.

Life progressed at this steady pace for quite some time. But one day, the researchers took notice of a particular species promcrab they named nepa rationabilis. These eight-legged creatures had evolved appendages with dexterous hooks that they used to weave nets of vines. To hunt prey, multiple nepa rationabilis would work together to cast these nets over larger creatures that passed by on the forest floor. The species also had a remarkable capacity for social interaction, living in groups of up to a hundred members. They would communicate through patterns of clicking sounds made with their hooks.

The researchers were thrilled to watch nepa rationabilis slowly master more complex tools such as spears and projectile weapons. Their language also evolved, becoming more intricate and expressive over time. This allowed them to form larger communities and specialize their skills. Instead of hunting, they began to cultivate their own crops, which contributed to a boom in the global rationabilis population. Without a doubt, this odd species of intelligent crab had become the dominant creature on Prom.

The rise of rationabilis very closely mirrored that of humans. In a short period of time – a blink of an eye in comparison with the trillions of exaticks it took them to evolve – the rationabilis species made a series of inventions that greatly improved their quality of life. They formed cities and countries. They had their own industrial revolution. They produced vehicles of transportation and terrible weapons of war. They invented “thinking machines” that could perform computations orders of magnitude faster than their own brains.

The human researchers in the Prometheus Colony tracked the progress of this species as well as they could. There were human experts who dedicated their lives to the study of the various Prom languages. Others specialized in the progress of Prom math, physics, and philosophy. Up to this point, the humans had achieved everything they had hoped for. Their experiment had produced intelligent life forms like themselves. But they never expected what came next.

The first interesting development occurred in Prom physics. Over time, Prom scholars studied the behavior of the world around them and slowly formulated a theory of Promethean physics. It started out simple (with theories of gravity and macroscopic motion), but they soon invented machines (essentially, microscopes) that allowed them to peer into smaller and smaller windows of their reality. They made hypotheses. They corrected their theories in light of new evidence. Eventually, they reached the realization that the fabric of their world consisted of discrete particles, which would flip back and forth according to simple deterministic laws. A theory of everything. They had unlocked the knowledge of the underlying bits and Laws that governed their existence.

The second development occurred in Prom philosophy. Just like human philosophy, Prom philosophy progressed in stages. There was a period when most Prom philosophers were theists, believing in a God which created their universe. Once Prom physicists discovered the underlying determinism of their universe, Prom philosophy shifted to become more atheist and dependent on science. The human researchers found it interesting that Prom philosophers seemed to have an easier time refuting free will than humans had. Yes, all rationabilis had the sensation of making their own choices, but since everything was deterministic, Prom philosophers simply treated that sensation as an illusion. There were even certain Prom philosophers who brought up the possibility that all of Prom was in a simulation, but this view was largely dismissed because there would be no way to verify it, even if it was true.

This is not to say that Prom philosophers denied consciousness. Quite the contrary – most Prom philosophers championed a moral framework in which the best action was the one that maximized the total happiness of conscious beings. The human researchers recognized this as a form of hedonistic utilitarianism. This philosophy was widely popular among the general population of rationabilis. Consciousness and determinism were not mutually exclusive, in the Prom view. Prom philosophers postulated that in any sufficiently complex system where information was strongly connected, such as a brain, a first-person consciousness would arise naturally.

This is when the breakthrough happened. Prom philosophers and physicists together realized that their entire reality was a finite deterministic system. The state of their universe in one tick, \(U(t)\), completely determined the state of their universe in the next tick, \(U(t+1)\). And in any such system, there eventually has to be a repeat: two ticks \(t_0 < t_1\) such that \(U(t_0) = U(t_1)\). A cycle in the transition graph. Once this happens, the state of the universe will loop forever and ever, trapped by the oppressive determinism of reality.

Without intervention by intelligent life, there was an overwhelming probability that this loop of fate would occur in the absence of interesting structure. In other words, it is highly likely that the first repetition of a universe state would appear during the “heat death” of Prom – after their planet breaks up and their entire universe consists of a soup of wandering molecules. To understand this, just take a finite version of Conway’s Game of Life with a complex initial setup. The repeating structure at the end is almost always boring.

The inhabitants of Prom didn’t want this. This would mean that the entire moral value of their existence would only ever be finite – that once this loop occurred, nothing would ever happen again. Instead of throwing up their pincers and saying “oh well,” as humans probably would have done, the entire race of nepa rationabilis was determined to keep moral value flowing through their universe forever. So they devised an incredible plan.

Using their complete understanding of the Laws of Promethean physics, they set out to design a periodic event with positive moral value. Their own biological brains were messy and inefficient, so instead, they decided to create a conscious artificial intelligence on one of their thinking machines. Their goal was not to make it superintelligent, but rather to be completely certain that it had consciousness – that its happiness had positive moral value. Once they had mastered the art of creating these new “feeling machines,” they sought to develop a single happy thought that a feeling machine could think that would eventually leave it in the exact same state it started in. A periodic thought.

This proved to be an incredibly difficult task. There are exponentially many states a thinking machine could be in, so finding even a single sequence of states that looped on itself seemed almost impossible. It took centuries of Promethean time, but the rationabilis species did not give up. They even created superintelligent thinking machines to help them with this search (this was quite a risky move, but fortunately they were able to successfully align these superintelligent agents to work with, not against, them). Finally, they found one. A single periodic thought – no, more like a sensation – that left a specific feeling machine in a perpetual state of mild happiness. The circuitry of this feeling machine was sealed off in a Box and seeded with this sensation so that it would continue to feel mildly happy forever. The state of the interior of the Box was completely periodic, as long as it received no external interference.

Once they had accomplished this, the inhabitants of Prom knew what had to be done. As long as they existed alongside the Box, the periodicity of the system was at risk. The Box could be broken or destroyed, denying it the infinite moral value it promised. There was only one solution: to set the entire universe around the Box into a periodic cycle in such a way that the barriers of the Box would never be penetrated. And there was a terribly simple way to do this.

With resolve, the rationabilis shut off their superintelligent thinking machines (the machines knew and agreed to what was happening, of course) and stopped reproducing. Eventually, all rationabilis had died to natural causes except one. This old crab, greyed with age, stood alone on his planet. Alone in his universe save a single Box repeatedly feeling a mildly happy sensation. He smiled as he detonated the bomb that his species had built beneath the surface of Prom. He smiled because he knew that the bomb was fueled by a chemical reaction that would destroy everything in his reality except the Box (the surface of the Box was coated with a special chemical – the only chemical in the universe resistant to this reaction). He smiled because, even though there would be no one left to see it, that little Box would continue to be happy, forever. Floating alone in a sea of bits set to \(0\), unchanging. Forever. The only changing thing in the universe would be the contents of the Box, but they would be changing in the same way over and over again, producing a happy sensation to infinity.

As the bits making up the last rationabilis were converted to \(0\)s at the Promethean speed of light, he smiled because he knew his race had achieved the last thing that would need to be achieved, ever. Infinite moral value.

And so it happened. By exatick \(6 \times 10^{13}\), the Simulation reached complete periodicity. A single machine, feeling the same sensation over and over. Slowly accumulating moral value, according to the utilitarian philosophy of Prom.

By the hundredth time the Box sensed its sensation, the humans outside grew bored. They had learned all they would ever learn from their overgrown science experiment. So they turned the Simulation off.